<!DOCTYPE html>
<html class=reftest-wait>
<meta charset="utf-8">
<meta name="assert" content="Position-visibility should not be affected by the visibility of a previous anchor." />
<title>CSS Anchor Positioning Test: position-visibility: anchors-visible</title>
<link rel="help" href="https://drafts.csswg.org/css-anchor-position-1/#position-visibility">
<link rel="match" href="position-visibility-anchors-visible-change-anchor-ref.html">
<script src="/common/reftest-wait.js"></script>
<script src="/common/rendering-utils.js"></script>
<style>
  #scroll-container {
    overflow: hidden scroll;
    width: 300px;
    height: 100px;
  }

  .anchor {
    width: 100px;
    height: 100px;
    background: orange;
    display: inline-block;
  }

  #anchor1 {
    height: 200px;
    anchor-name: --a1;
  }

  #anchor2 {
    anchor-name: --a2;
  }

  #target {
    position-anchor: --a2;
    position-visibility: anchors-visible;
    position-area: bottom;
    width: 100px;
    height: 100px;
    background: green;
    position: absolute;
    top: 0;
    left: 0;
  }
</style>

<div id="scroll-container">
  <div id="anchor1" class="anchor">anchor1</div>
  <div id="anchor2" class="anchor">anchor2</div>
  <div id="target">target</div>
</div>

<script>
  // #target should be initially visible because it is anchored to #anchor2,
  // which is visible.
  waitForAtLeastOneFrame().then(() => {
    // Change #target to be anchored to #anchor1.
    target.style.positionAnchor = '--a1';
    // #target should be still be visible because #anchor1 is also visible.
    waitForAtLeastOneFrame().then(() => {
      // Scroll #anchor2 out of view, with #anchor1 still in view.
      const scroller = document.getElementById('scroll-container');
      scroller.scrollTop = 100;
      // #target should still be visible because it is anchored to #anchor1,
      // which is still visible.
      takeScreenshot();
    });
  });
</script>
